arm/stm32f401rc-rs485: Add support to LCD 16x2 with I2C Backpack

[rcsim]

Summary

Add support to LCD 16x2 with I2C Backpack

Impact

Users will be able to use LCD 16x2 with I2C Backpack on SMT32F401RC-RS485 Board

Testing

Configure lcd1602
Build and Flash
Run slcd example:

nsh> slcd "Hello NuttX"
Opening /dev/slcd0 for read/write access
Attributes:
  rows: 2 columns: 16 nbars: 0
  max contrast: 0 max brightness: 1
Clear screen
WRITING:
0000: 1b5b46                                                            .[F
Set brightness to 1
Print [Hello NuttX]
WRITING:
0000: 1b5b471b5b30304c1b5b4548656c6c6f 204e75747458                     .[G.[00L.[EHello  NuttX
Test complete
nsh>

[nuttxpr]

[Experimental Bot, please feedback here]

The PR as presented does not meet the NuttX requirements fully. Here's why:

Missing Information:

• Summary:

  • Why is this change necessary? Is it a new feature request? Are there existing issues with LCD support?
  • What functional part is changed? Be specific - mention the driver(s) modified or added.
  • How does the change work? Explain the technical implementation (e.g., "Added an I2C driver for the LCD backpack and integrated it with the framebuffer driver").

• Impact:

  • The current description is too vague.
  • Which architectures/boards are affected specifically?
  • Build impact? Are there new Kconfig options?
  • Documentation? Was any added/updated to reflect the new LCD support?

• Testing:

  • Insufficient detail!
  • Build Hosts: List the specific OS, CPU architecture, and compiler versions used for testing.
  • Target(s): Provide the exact architecture (e.g., armv7-m), board name (e.g., stm32f4discovery), and the NuttX configuration used (e.g., stm32f4discovery_defconfig).
  • "Testing logs before change" are irrelevant. There wouldn't have been LCD output before this feature.

Recommendations:

1. Expand the Summary: Provide a clear, technical overview of the changes made.
2. Be Specific about Impact: Clearly list all affected architectures, boards, drivers, Kconfig options, and documentation.
3. Detailed Testing Info: Follow the template, providing complete information about your build and target environments.

Example Improvement:

## Summary

This PR adds support for 16x2 LCD displays with I2C backpacks to the STM32F401RC-RS485 board. 
It achieves this by:

1. **Adding a new I2C driver** for the specific LCD backpack used (mention the chip/model).
2. **Integrating the LCD driver** with the NuttX framebuffer driver to enable text output. 
3. **Adding a new board configuration option** (`CONFIG_VIDEO_LCD1602_I2C`) to enable this feature.

This change addresses [link to NuttX issue or feature request, if applicable].

## Impact

* **New feature:** Support for 16x2 LCDs with I2C backpacks.
* **Impact on user:** Users with the supported LCD and board can now use it for display output.
* **Impact on build:**
    * New Kconfig option: `CONFIG_VIDEO_LCD1602_I2C`
* **Impact on hardware:**
    * **Architectures:** ARM (specifically ARMv7-M)
    * **Boards:** STM32F401RC-RS485
* **Impact on documentation:**
    * Added a new section to the STM32F401RC-RS485 board documentation explaining how to configure and use the LCD.
* **Impact on security:** None
* **Impact on compatibility:** None 

## Testing

I confirm that changes are verified and work as intended:

* **Build Host(s):**
    * OS: Ubuntu 20.04
    * CPU: Intel Core i7-10700K
    * Compiler: GCC 9.4.0
* **Target(s):**
    * Architecture: armv7-m
    * Board:  stm32f401rc-rs485
    * Configuration: `stm32f401rc_rs485_defconfig` with  `CONFIG_VIDEO_LCD1602_I2C=y`

**Testing logs after change:**

nsh> slcd "Hello NuttX"
Opening /dev/slcd0 for read/write access
Attributes:
rows: 2 columns: 16 nbars: 0
max contrast: 0 max brightness: 1
Clear screen
WRITING:
0000: 1b5b46 .[F
Set brightness to 1
Print [Hello NuttX]
WRITING:
0000: 1b5b471b5b30304c1b5b4548656c6c6f 204e75747458 .[G.[00L.[EHello NuttX
Test complete
nsh>

By providing this level of detail, you make it much easier for the NuttX maintainers to understand, review, and ultimately merge your contribution.